Means for roasting coffee



Nov. 17, 1942. R. ATTl 2,301,922 MEANS FOR ROASTING COFFEE Filed Oct 5, 1939 2 Sheets-Sheet 1 ATTORNEY Nov. 17, 1942. R. ATTI 2,301,922

I MEANS FOR RQASTIQING COFFEE Filed Oct. 5, 19:59 Z'Sheets-Sheet 2 122 g 122 I 7 27 96 illlll F INVENTOR I? P/m nfl ATTORNEY Patented Nov. 17 1942 'UNITEDYSTATES PATENT OFFICE,

MEA\TS FOR ROASTING COFFEE 'Raphael Atti, Gliffside Park, N. J., assignor to William D. Breaker, Brooklyn, N. Y.

Application October 5, 1939, Serial No. 297,991

1 Claim. -(Cl. 99236) tion to provide an improved method for roast.

ing coffee and to provide an improved machine for carrying out such method, whereby a predetermined quantity. of coffee may with facility be subjected to a roasting treatment for a predetermined period and at a predetermined temperature so that all of the coffee beans may be uniformly roasted, that is, subjected to the same of roasting whereby not only the coffee portion advanced at the beginning of a predetermined supply, but also the coifeeportions positioned in the intermediate stages of advance, and the coffee portions positioned at the end or final stage of advance of a predetermined supply, will all receive a uniform roasting treatment not only as to temperature but also as to time.

It is also an object of the present invention to provide an improved method for roasting coffee and to provide an improved machine to carry out such method, whereby no extraneous gases of combustion will be admitted to the coffee roasting chamber during its roasting period, and on the; other hand the volatile matters including gases released by the coifee beans during the roasting process be confined against escape from the roasting chamber so that the cofiee beans during the roasting period will actually be roasted in an atmosphere saturated with the gases or volatile matters released by the coffee beans, that is, with a view to retarding if possible the release of such gases from the coffee beans and thereby to enrich the aroma and in turn the flavor of the ultimate roasted coffee beans.

More specifically, it is an object of the present invention to provide an improved machine for roasting coffee in which in a comparativelysmall chamber a predetermined quantity of coffee beans may be passed a number of timeswith each bean individually exposed to the heat-transmitting gases of the chamber, and whereby at the same roasting temperature and for the same period particles of the green bean introduced, are effectively removed during the roasting process.

Specifically, it is still another object, of the present invention to provide a machine for roasting jcoifee having a plurality of concentric pas-. sagesprovided with spirals for directing the. coffee through the several concentric passages. from ,one to the other, whereby the individual beans of a predetermined quantity may be efiectively separated, exposed to. the heat-transmitting gases, and in turn a predetermined limited 3.183, used to the best advantage for, an extensive composite passage, of the:coifee composed of the several concentric passages.

Specifically, it is still anotherobject of the present invention to provide animproved machine for roasting coffee, having, a plurality of.

concentric foraminous drums mounted upon .a

rotatable shaft and having spiralsfor advancing a predetermined quantityof coffee through these several drums while roasting the same so that some of the chaff of the coffee bean may be removed while the coffee bean is being tumbled in contactwith the foraminous walls of the drums. and, additional pneumatic means provided for.

supplementing the removal of the chaff from the bean as the bean is finally discharged from the roasting chamber. j

These and other features, capabilities and advantages of the improved method for roasting coffee and of the machine for carrying out such method will appear from the subjoined detail description of one embodiment of the invention illustrated in the accompanying drawings in p which Fig. 1 is a longitudinal section of the coifee roasting machine;

Fig. 2 is a section on the line 22 of Fig. 1;

Fig. 3 is a section on the line 33 of Fig. 1;

Fig. 4 is a section on the line 44 of Fig. 3; Fig. .5 is a section on the line 55 of 'Fig. 3;

and

Fig. 6 is a diagram of the wiring for the heating unit, motor and thermostat associated with the improved coffee roasting machine.

In the embodiment illustrated, there is pro vided a main housing I, having a front wall 2 and. rear wall 3,,two side walls 4 and. 5, and an upper wall 6. These several wall elements 2, 3, 4,

v 5 and 6, may be composed of metal and connected to one another in the usual way. The upper wall 6 is preferably provided with an elongated opening near the wall 2 to receive the funnel-shaped extension I of the hopper 8. The wallfi also time the chair, and particularly the fuzzyouter 55,..preferably has a round opening at its rear end inner face of the rear wall 3, and only extending down along the front wall 2 to a point just immediately above the door opening for the door III. This insulation may be composed ofmagnesiumv rock, rock wool, asbestos, or the like. Fdl s e blll f ing this insulation I2 in position preferably the inner face of the insulation I2 is provided'with a metal sheet such as the sheet l3 below the wall 6,

the sheets I4 and I5 inside of the walls l and? respectively, andthe sheetIE inside of the wall 2. Extending down from the sheet I3 substantially parallel to the main portion of the rear wall 3, but-spaced therefrom to form a chamber, there is provided the metal partition IT. This partition extends the full-width of the housing I and is disposed forwardly of the opening for the cylinderfi to provide an air passage from the opening through the cylinder 9 .down through the housing between the wall B and partition Ill.

The chamber 58 formed between the partition IT and wall 3 also contains the motor I9 secured by the bracket 2E3 to the rear facefof the partition I7, and having a transmissionigearing in the extension 2| provided with the shaft 22 on which is mounted the pinion 23in mesh with the pinion 24 on the main driven shaft 25 of the coffee roasting chamber. The shaft 26 of the motor I9 at its upper end has secured thereto the fan Z'Lpreferably of the sirocco type, which isdisposed immediately below the opening for the cylinder 9 to draw air inward through the cylinder 9 into the chamber I8 in a downward direction. The lower end of the wall 3 is preferably provided with a door opening for the door 28 hingedly connected at 29 at its lower end to afford access as an instance to the lower end of the motor and power transmitting gears. Preferably, the collar 9 is provided with a cap dflhaving an opening 3! provided with a suitable foraminous sheet 32, to permit the passage of air but prevent the wrongful admission of objectionable paper, destructive elements and the like.

The lower end of the chamber I8 is provided with two deflecting baffies 33 and 34, the bafile 33 being provided to deflect the air passing down through the chamber i8 into the basket 35 for receiving the finally roasted coffee beans. The basket 35 as shown is preferably composed of foraminous material, and rests on inwardly extending webs of the angle-irons 36 secured to the legs 3! at the rear end extending down from the rear corners of the housing I, and the legs 38 extending down from the front corners of the housing I.

To form a heat conserving roasting chamber or compartment, there is secured to the inner sheets I3,' I4 and I5, the insulating partition consisting of the outer metal layers 39, 25 and intermediate insulation 4|. 'This partition G2 extends down just rearwardly of the funnel i of the hopper 8 and down to' a level, in the present instance, slightly below the level of the lower nd of the inner sheetI". This partition d2 has a central opening to clear the collar 43 having a conical opening BA flaring outward axially in a rearward direction relative to the front wall 2. Forwardly of the sheet 355 of the partition 42 there is provided the bracket in the present instance consisting of a block 45 through which the front end of the shaft 25 is journalled extending into the roller bearing housing 46 secured to the forward end of the bracket 45. This bracket 55 has a downwardly inclined face il to receive the coffee beans as they are fed thereto by the funnel l, and then pass it on to the flaring wall 44 of the collar 43 in turn to pass it on to the inner and first of a series of concentric chambers.

Just forwardly of the partition I'l, the rear wall 58 of the roasting chamber is provided, it in cluding the outer metal walls 69 and 58 enclosing the inner insulation portion 55. This wall 58 extends closely adjacent to the partition I"! and extends inwardly from the inner sheets I3, I4 and I5. Itis provided with a large circular opening concentric to the opening in the. front partition Q2to clear thecylindrical portion 520i the disc 53 mounted on the shaft 25. Securedto the partition. I7 and adjacent .to the disc53 is the roller bearing li ifor receiving the shaft 25. In order to heat insulatetherearface of the disc 53 from the partition I7, an annular section 55 of insulation is'secured to therear face ofthe disc 53 and just clears .the .rollerbearing housing 5d. The

lower. end of .the partition 48 extends down bemidway between the sheeting 39 and sheeting I6.

The partition. 5Sat its forward portion below the partition 42 is spaced therefrom, as particularly shown inFig. 1, to form an entrance for a drawer Gd consisting of a metal box open at the top and having an insulated front wall 6! consisting of .the 'sheetings52, 63and the insulation 64 therebetween. The front metal sheet 65 in front of the sheetingGZ in the present instance extends down below the partition 6i and continues on into the lower metal floor 680i the drawer Bi). The lower face .of the drawer fidis comparatively smooth in order readily to slide on the upper face of the sheeting 57 of the floor member 56 of the roasting chamber-.- in order to facilitate removing the drawer Gilwhen desired, there is formed a handle G'I-at its front end which may be grasped when the door it is opened to withdraw the drawer from its place at the bottom of the roasting furnace throughthe door opening of the door Ill.

In the roasting chamber 68 formed by the upper wall 6 and its sheeting l3 and insulation I2, the side walls 4 and 5 with their insulation and inner sheetings, the front and rear partitions i2 and 48 respectively, and the floor partition 56, there'is provided a drum 69 fixed to rotate with the shaft 25. The drum (see Fig. 2) consists of three cylindrical concentric foraminous layers it,

II and 12. The cylindrical layer 76 is fixed at one end to the collar 43 and at the other end to the oollar'i3 fixedon-the shaft 25. The foraminous layer i0 is spaced from the shaft 25 and secured thereto bythe metal spiral sheet 74 which preferably has thirteen spirals in its extent from the collar '43 to the collar 73 and inclined when rotated in a counter-clockwise direction whenlooking from the rear, to advance the coffee beans in a rearward direction. It is herein to be noted that the chamber formed by the cylindrical layer 10 is concentric to the conical opening in the collar 43 to receive the coffee as it is fed through the hopper 8, funnel I, and mouth formed by the block 45 and collar 43.

At the rear end of the cylindrical layer I immounted upon the cylindrical sheet I0 adjacent to the collar ,43 and in turn to the rear face of the annular disc 18 mounted upon the cylindrical sheet [0 adjacent to the collar 43. The collar I1 in turn is mounted upon the rear end of the cylindrical sheet I0 more or less in alignment with the collar I3 and secured to the front face of the disc 53. This cylindrical-foraminous sheet II is definitely spaced from the foraminous sheet I0 by the spiral sheet I9, likewise having thirteen spirals extending from the collar 71 at the rear to the collar I3 at the front, and inclined so that when the drum 69 i rotated in a counter-clockwise direction when looking from the rear, the coffee beans received through the opening I5 from the chamber Within the cylinder I0, will be fed forwardly. Adjacent the forward end of the cylindrical sheet II and adjacent to the rear of' been advanced to the front end of the cylinder I I.

Radially outward of the cylinder II, the cylindrical foraminous sheet I2 is secured at its front end to the annular flange 8| of the disc 70 and at its rear end to the inner face of the flange or cylindrical portion 52. In addition, the cylindrical sheet I2 is spaced from the cylindrical sheet II by the spiral sheet 82 extending throughout the length of the cylindrical sheet 72 from front to rear and consisting of thirteen spirals inclined so that when the drum 69 is rotated in a counterclockwise direction looking from the rear, the coffee beans received through the opening 80 from the cylinder II are fed in a rearward direction.

At the rear end of the cylindrical sheet I2 in the disc '53, there is formed a small opening 83 through which the coffee beans are finally discharged after the roasting treatment has been completed. The beans so discharged then pass adjacent the front face of the partition I'I down into the basket 35. While so passing dOWn into the basket 35, the portion of the stream of cool air passing downthe chamber I8 which strikes the baffle or deflector 34, is directed laterally with suflicient force to free the final chaff or objectionable particles from the coffee beans, and direct them into the basket 84 through its open end 85 at the rear. The coffee beans, after being so subjected to this draft of cool air, pass down into the basket 35. The basket 94 (see Fig. 2) is provided with laterally extending flanges 85 and 86 to rest on the inwardly extending webs 81 and 98 respectively of the angle-irons 89 and 90 extending along the inner lower ends of the walls 4 and 5. The front end of the basket 84 is provided with a handle 9| to facilitate the removal of the basket forwardly along the angle-irons 89 and 90.

From the foregoing it will appear that the coffee beans as they advance rearwardly along the cylinder I0, forwardly along the cylinder II, and

the other main lead I08.

again rearwardly along the cylinder I2, will be guided in such movement due to the inclination of the several spiral sheets I4, I9 and 82, remain along the lower ends of said cylinders, through- I out their movement, tumble along due to the foraminous nature of the sheets 10, H, and I2, thereby to free themselves of the chaff or outer objectionable fuzzy matter which will drop from one cylinder to the other until it finally drops into the drawer 60, from there to be removed. It will also appear that whatever flaky, fuzzy particles may still adhere to the bean after leaving the opening 83, will be substantially removed by the air stream directed by the deflector 34 which fuzzy particles will then be received by the basket 94 and from there be removed, and that the finally roasted bean will then be received in the basket 35 there to be finally cooledby the air blast coming down the chamber I8, the foraminous nature of the wall structure of the basket 35 facilitating the ready passage of the cooled air through the basket 35, and the ready removal of the air so heated by coming in contact with the heated beans in the basket 35.

The heating arrangement will now be described. The chamber 68 is preferably heated by a heat transmitter which will not distribute or circulate any products of the heating medium in the roasting chamber 68. In the present instance, an electrical heating unit is provided, consisting of the heating wires 92 and 93. The heating wire 92 (see the diagram illustrated in Fig. 6) is connected by the conductor 94 to the main lead 95 and (see Fig. 4) is preferably Wound .upon the two parallel rods and 91 mounted in the supporting plates 98 and 99 secured to the sheeting I5 to one side of the drum 69. The other heating wire'93 is connected by the conductor I00 to the main lead and wound upon the rods ml and I02 '(see Fig. 4), which are mounted in the aforesaid supporting plates 90 and 99. The ends of the heating wires 92 and 93 which are not connected to the main lead 95 are, as an instanceas shown, connected to the common conductor I03 which in turn is connected to the contact I04 to be engaged by the switch arm- I05 which is connected to the contact I05 which is connected by the conductor I0'I to The switch arm I05 normally engages the contact I04 when the switch I 24 is closed and the electro-magnet I09 is'energized, one end of the winding of the electro-magnet I09 being connected by the conductor I I0 to the conductor 94, and the other end of the winding of which being connected by the conductor III'to the bimetallic thermostat II2 mounted in the housing II3, provided with the control dial H4. The other terminal of the bimetallic thermostat H2 is connected to the.

conductor II5. In other words, depending upon the speed of the motor I9 and the consequent feed through the roasting chamber of a predetermined unit of coffee, the temperature can be regulated by the regulating dial II4. If the heat in the roasting chamber 68 exceeds this predetermined temperature then in the regular way the thermostat I I2 will interrupt the current to the electro-magnet I09 to de-energize the electro-magnet I09 to release the arm I05 to interrupt the electric circuit to the heating wires 92 and 93 and permit the temperature to drop, and in turn when the temperature has dropped sufficiently, the thermostat I I2 will again close the circuitof the electro-magnet I09 to actuate the arm I05 to engage the contact I04 to re establishthe electric currentfor the heating wires 92 and 93.

The-wiring diagram in Fig. 6 also shows the motor l9 connected to the main leads 95 and E68, one terminal of the, motor it being connected by the conductor lit to the contact lilfi which is connected by the conductor ill? to the mainlead Hi8, and the other terminal'of the motor l9 being connected by the conductor ill to theconductor 94 which is connected to the other main; lead 95.

In order to prevent the beans in the drum 89 being subjected to radiant heat and thereby effeet a fairly uniform heat throughout the roasting chamber, there isprcvided a sheet metal plate H3 secured to the inner ends of the supporting plates 95 andtii sufficiently removed from theheating units 92 and 93 so that this plate l it cannot become incandescent and transmit radiant heat to the beans being roasted.

The hopper 8 is preferably provided with a flanged. cover-supporting collar M9 to receive the cover i253 preferably having a thickness [2i of steel wool to shut off the escape of the volatile gases resulting during the roasting of the coffee. This cover E29 is provided with a handle i212 to remove the same when desired.

From the foregoing, it will thus appear that the coffee being roasted'is subjectedto a heat transmitted by the gases or air contained in the chamber fiflwhich in turn are heated either by contact withthe heating, wires 92 and Q3 or radiant heat from such heating wires E2 and 93. Italso, will appear that the coffee will not in any way be subjected to anyradiant heat. One reason for protecting the coffee beans from radiant heat isthat it iskpractically impossible to uniformly heatathe entire surface of a coffee bean due to its conformation by radiant heat. This would be so whether the drum 68 were surrounded by a radiant heat transmitting element or not, since it is of, course obvious that onlyone, face of a coffee bean can be exposed to the radiant heat even insuch case. Froma practical standpoint, however, the heating unit disposed, at one side of the chamber 68, as here illustrated, and enclosed-so that all radiant heat will be shut off from the bean, will facilitate the uniform roasti'ngofthe entire surface of each individual coffee bean without the danger of burning anyportion thereof, It will also appear that with the heating unitsuch as thepresent, no foreign products of; combustion such as will becreated in the burning of gas or the like, can possibly surround the coffee bean being roasted and thereby contaminate the same. It is of course well known-that the coffee bean when roasted is a spongy, absorbent substance, and will readily absorb such products of combustion so that the average coffee-taster can readily detect such contamination. Here, the coffee bean is subjected to a heated atmosphere consistingmainly of air saturated with the volatile'fumes or gases which may be released by the coffee during roasting-.- Consequently, in the final stage of the roasting process, when the bean would be most likely to absorb foreign substances, it can only absorb particles suspended in the volatile gases and fumes released by itself thereby, if anything, to replenish it with any of its coffee ingredients which it may have lost during the roasting process, I

i From Fig. 1 it will clearly appear that the only outlet for any of the heated gases'contained in the roasting chamber, will be through the small 75:

opening '83 in the disc 53,- wic-ch opening will; be substantially shut off at least a part of the time when the coffee beans are being discharged therefrom in the position illustrated in Fig. l.

The opening forwardly through the collar 43,

however, to mention that excellent results have been achieved when the length of the drumis substantially seventeeninches, the diameter of' the inner cylindrical sheet l9 about three inches,

the diameter of the intermediate cylindrical sheet ii-about five and one-quarter inches, and the diameter of the cylindrical sheet 72 about eight inches. With the drum having the dimensions as aforesaid and the consequent extended passage,

provided by the spirals i i, 19 and 82, and with a temperature of about four hundred degrees, and

a speed of rotation for the drum of about 4 R. P. M., it has been found that itrequires about eight minutes to feed a predetermined unit of coffee from the collar d3 into the basket 35, and properly roast it. The openings from one cylinder to the other, as an instance the openings 15 and 3d, are preferably about one and threeeighths inches by two inches. Preferably, the mesh of the several foraminous sheets should not exceed a mesh having openings of one-eighth inch in diameter.

The motor 49 is preferably provided with a rheostat l23 to control the speed of the motor l9 regulatedrelative to the temperature determined.

It is obvious thatvarious changes and modifi cations may be made to the details of construction of the improved machine for roasting coffee and in the steps ofthe improved method for roasting colfee, hereinabove described, without departing from the general spirit of the invention as set forth in the appended claim.

I claim:

The combination with an enclosed roasting furnace, a drum extending through said furnace for receiving the coffee beans being roasted means for heating said furnace, means for rotating said drum, a spiral in said drum for advancing the beans through said drum and thereby through said furnace while being roasted, a hopper having a funnel for supplying the coffee, beansto said drum, a discharge outlet for the drum extending out of the furnace, a basket registering with said outlet to receive the beans as they are discharged, means forming an air passage disposed adjacent to said furnace with an opening at the top thereof, a motor drivingly connected to said rotating means mounted in said passage, 2. fan connected to saidmotor and positioned; to direct a blast of air downwardly, deflectorsat the lower end of said passage, one of said deflectors receiving and deflecting part of the blast of air laterally upon the beans as they drop from outlet into said basketto remove any fuzzy particles that might still cling to the beans, and the other deflector directing a blast of air onto the coffee beans in the basket to cool the same.

RAPHAEL ATTI. 

